Temperatures across the Midwest this morning range from the 20s and 30s across northern areas with some lower 40s across southern regions. Most of us will be greeted by abundant sunshine this morning, with sun across western areas fading this afternoon as a high cloud deck thickens ahead of the next significant winter storm.
This evening, a deepening upper-level trough will spawn cyclogenesis across the Kansas/Oklahoma borders. As this surface low begins to deepen, warm humid air from the Gulf will be driven northward into eastern portions of the southern Plains/western Mississippi Valley. Showers and thunderstorms wil develop near the Kansas/Missouri borders, increasing in coverage along a sharpening warm front across northern Missouri and eventually southern Iowa and central/northern Illinois through Thursday morning. An axis of 0.5- to 1.0-inch rainfall will unfold across these areas. This locally heavy rainfall will work in tandem with rapid snowmelt and frozen soils to produce flooding across portions of central and northern Illinois.
Frozen rivers will rise quickly through the day Thursday with impacts to river transportation an increasingly likely scenario. In addition, eastern Illinois will be under the gun for strong afternoon thunderstorms as a potent cold front collides with warm and modestly unstable air from the south. An extensive squall line will likely develop across the central Midwest southward into the northern Gulf States, bringing with it the potential for damaging winds across the Delta region north and east through the Ohio Valley. Temperatures in these areas will spike into the 50s and 60s with rapid snowmelt likely for central and southern portions of the Ohio Valley.
Farther west on the cold side of this developing system, rain will change to sleet then snow across central Iowa late Thursday morning, resulting in a relatively brief but heavy burst of snow. The greater Des Moines metro will be heavily impacted late Thursday morning through the early afternoon as 1- to 2-inch snowfall rates in addition to strengthening northwest winds create blizzard-like conditions. While 2 to 5 inches of accumulation is possible near Des Moines, 4 to 8 inches is possible across northeast Iowa with at least 6 inches for southern Minnesota and western Wisconsin.
Blizzard conditions are likely in these areas, which will result in nearly impossible travel Thursday evening into Friday morning. Behind this system, seasonable weather will be in place Friday with a gradual cooling trend this weekend. Next week, an abnormally cold pattern will plague the northern U.S. as a rapidly amplifying ridge across Alaska forces another trough of misfortune into the Upper Midwest and Northern Plains. Through next week into the beginning of March, this axis of bitterly cold air will gradually shift eastward into the Eastern states.
Temperature anomalies will approach 10 to 20 degrees below normal for the northern U.S. during the six- to 10-day time frame, shifting eastward toward the Atlantic Seaboard for the 11- to 15-day time frame. Winterkill threats with this late-season cold surge seem rather limited at this time, with the best chance across northern SRW wheat areas.
